Production method of anisotropic conductive sheet

1. A method of producing an anisotropic conductive sheet, which method comprises: (a) placing a flowable insulating resin in a space of a sheet-like molding die, wherein the flowable insulating resin has conductive magnetic particles dispersed therein, (b) simultaneously performing, relative to the space of the sheet-like molding die, the processes of (i) applying, in a sheet thickness direction, a first magnetic field to a position in the space of the sheet-like molding die to locally collect the conductive magnetic particles together to form a conductive path, and (ii) applying, in the sheet thickness direction, a second magnetic field to a region in the space of the sheet-like molding die and moving the second magnetic field in the sheet surface expanding direction to move the conductive magnetic particles in the region to the conductive path formed in process (i), and repeating processes (i) and (ii) on a different portion of the flowable insulating resin, and (c) solidifying the flowable insulating resin to produce an anisotropic conductive sheet comprising an insulating resin sheet and conductive magnetic particles contained in the sheet, wherein the conductive magnetic particles are locally collected together to form multiple conductive paths penetrating the insulating resin sheet in the thickness direction, wherein the process (i) is performed by placing, according to the arrangement pattern of the conductive path, a first magnet in or behind a first main wall surface of two main wall surfaces forming the space of the sheet-like molding die, when seen from the space of the sheet-like molding die, and the process (ii) is performed by placing a second magnet behind the first magnet or behind a second main wall surface opposite the first main wall surface, when seen from the space of the sheet-like molding die, and moving the second magnet in the sheet surface expanding direction.

2. The production method of claim 1 , wherein the process (i) is performed by placing, according to the arrangement pattern of the conductive path, the first magnet behind the first main wall surface, when seen from the space of the sheet-like molding die, and the process (ii) is performed by placing the second magnet behind the first magnet, when seen from the space of the sheet-like molding die, and moving the second magnet in the sheet surface expanding direction.

3. The production method of claim 2 , wherein a die member forming at least the first main wall surface is made of a material permitting passage of a magnetic field from behind.

4. The production method of claim 1 , wherein the process (i) is performed by placing, according to the arrangement pattern of the conductive path, the first magnet behind the first main wall surface, when seen from the space of the sheet-like molding die, and the process (ii) is performed by placing the second magnet behind a second main wall surface opposite to the first main wall surface, when seen from the space of the sheet-like molding die, and moving the second magnet in the sheet surface expanding direction.

5. The production method of claim 4 , wherein die members forming the first and second main wall surfaces are made of a material permitting passage of a magnetic field from behind.

6. The production method of claim 1 , wherein at least the sheet-like molding die, the source of the first magnetic field and the source of the second magnetic field are partially or wholly surrounded by a magnetic material so that the first magnetic field and the second magnetic field will act more intensely on the space of the sheet-like molding die.

7. The production method of claim 1 , further comprising adding mechanical vibration to the space of the sheet-like molding die to facilitate the process (ii).

8. A method of producing an anisotropic conductive sheet, which method comprises: (a) placing a flowable insulating resin in a space of a sheet-like molding die, wherein the flowable insulating resin has conductive magnetic particles dispersed therein, (b) simultaneously performing, relative to the space of the sheet-like molding die, the processes of (i) applying, in a sheet thickness direction, a first magnetic field to a position in the space of the sheet-like molding die to locally collect the conductive magnetic particles together to form a conductive path, and (ii) applying, in the sheet thickness direction, a second magnetic field to a region in the space of the sheet-like molding die and moving the second magnetic field in the sheet surface expanding direction to move the conductive magnetic particles in the region to the conductive path formed in process (i), and repeating processes (i) and (ii) on a different portion of the flowable insulating resin, and (c) solidifying the flowable insulating resin to produce an anisotropic conductive sheet comprising an insulating resin sheet and conductive magnetic particles contained in the sheet, wherein the conductive magnetic particles are locally collected together to form multiple conductive paths penetrating the insulating resin sheet in the thickness direction, wherein the process (i) is performed by placing, according to the arrangement pattern of the conductive path, a first magnet in or behind a first main wall surface of two main wall surfaces forming the space of the sheet-like molding die, when seen from the space of the sheet-like molding die, and the process (ii) is performed by arranging multiple electromagnets as second magnets in the sheet surface expanding direction behind the first magnet or behind a second main wall surface opposite the first main wall surface, when seen from the space of the sheet-like molding die, and moving the second magnetic field in the sheet surface expanding direction by controlling the order of activation of individual electromagnets.

9. The production method of claim 8 , wherein the process (i) is performed by placing, according to the arrangement pattern of the conductive path, the first magnet behind the first main wall surface, when seen from the space of the sheet-like molding die, and the process (ii) is performed by arranging the multiple electromagnets as second magnets in the sheet surface expanding direction behind the first magnet, when seen from the space of the sheet-like molding die, and moving the second magnetic field in the sheet surface expanding direction by controlling the order of activation of individual electromagnets.

10. The production method of claim 9 , wherein a die member forming at least the first main wall surface is made of a material permitting passage of a magnetic field from behind.

11. The production method of claim 8 , wherein the process (i) is performed by placing, according to the arrangement pattern of the conductive path, the first magnet behind the first main wall surface, when seen from the space of the sheet-like molding die, and the process (ii) is performed by arranging the multiple electromagnets as second magnets in the sheet surface expanding direction behind the second main wall surface, when seen from the space of the sheet-like molding die, and moving the second magnetic field in the sheet surface expanding direction by controlling the order of activation of individual electromagnets.

12. The production method of claim 11 , wherein die members forming the first and second main wall surfaces are made of a material permitting passage of a magnetic field from behind.

13. The production method of claim 8 , wherein at least the sheet-like molding die, the source of the first magnetic field and the source of the second magnetic field are partially or wholly surrounded by a magnetic so that the first magnetic field and the second magnetic field will act more intensely on the space of the sheet-like molding die.

14. The production method of claim 8 , further comprising adding mechanical vibration to the space of the sheet-like molding die to facilitate the process (ii).